What is 1! (1 factorial)?
1 — 1 factorial (1!) equals 1. A factorial is the product of all positive integers from 1 up to the given number. Factorials are used in probability, combinations, permutations, and many areas of mathematics.
This calculation was generated using our Factorial Calculator. For custom values or more complex scenarios, try the full interactive calculator.
Below is the step-by-step calculation used to determine the result.
Answer
1
1! = 1 = 1
Step-by-Step Solution
1
1! is defined as 1 by convention
2
The factorial of 1 equals 1
3
Therefore, 1! = 1
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